Power driven hack saw



March 4, 1941. `J. H. GUILTMAN POWER DRIVEN HACK SAW 2 Sheets-Shes?l 1 Filed OCT.. 18', 1939 Inventor fn 'a///wan torneys March 4, 1941. J. H. GUILTMAN POWER DRIVEN HACK SAW Filed Oct. 18, 1939 2 Sheets-Sheet 2y ln ventor 17d-n gaf/7L??? c??? fwm A torneys Patented Mar. 4, y1941 I UNITED STATES PATENT OFFICE POWER DRIVEN HACK SAW John Henry Guiltman, Spokane, Wash. Application October 18, 1939, Serial No. 300,056 4 claims. (ci. .2a- 73) This invention relates to a power driven hack partition I is arranged in the upper portion of saw, the general object. of` the invention being the part 1 and the central portion of this partition to provide a base member, a saw carrying frame I0 has a hole therein for the passage of a shaft vertically movable on the base member and hav- I I which carries at its upper end a beveled gear 5 ing a horizontal part for extending over the ob- I2, the teeth of which are arranged as shown 5 ject to be sawed, a saw carrying member more specifically in Figure4 for engagement with supported for horizontal movement by said a beveled gear I3 on a horizontal shaft I 4 jourhorizontal part and means for reciprocating the naled in a side of the upper part of the member saw carrying member and for moving the hori- 'l and which shaft I4 is connected to an electric 1U zontal part of the frame vertically so that the motor M contained in a casing I5 attached to a 1 saw blade' can be moved downwardly against side portion of the frame A at the junction of the the object to be sawed at the same time the saw Dart 6 With .the part 1. This shaft I4 with the carrying member is being reciprocated, armature of the motor can be turned by hand Another Object ef the invention is t0 provide when and if desired as the motor shaft is extended l" means for slightly lifting the saw carrying memas shown' at I6 in Figure 2 through an extension ber on one stroke thereof so as to have the saw n 0f the Casing l5 and the Crank handle I8 cut only on one stroke. is adapted t0 be placed in a socket in the extension This invention also eensigts in Certain other I'I and into engagement with the shaft I6r so .that features of construction and in the combination by turning the Crank I8 the armature of the motor and arrangement of the several parts to be hereand the Shaft '4 Can be turned t0 tum the gear 20 inafter fully described, illustrated in the accom- I3 by hand. panyng drawings and specicauy pointed out in The SafW Carrier S Shown at and S Of the the appended eiaimg general shape of a hack saw frame and the blade In describing the invention in detail, reference is Shown at 20 and is Connected t0 the Carrier will be had to the accompanying drawings where- '9 in the uslal 01 any desired manner- At one 25 in like characters denote like or corresponding llvhcls' 121.51 gfgrgeegsh I? lorgltshank arts throughout the several Y views, and in i an erme' vhich: diate part of the portion 'I of frame A under the Figure 1 is an elevation with parts in Section partition I0 so that the carrier I9 is guided as it of the invention reciprocates and the top part of the carrier slides 30 Figure 2 is a Section on the une 2 2 of Fg along the under part of the portion 6 of the ure l. f frame A and an upright part 23 extends from i 1. the top portion of the carrier I 9 into' a recess urlure 3 1S a Secton on the me 3 3 of F 1g 24 in the bottom part of the portion e and ash'ank 25 extends horizontally from this part 23 and 35 urlure 4 1S a sectlon on the Ime 4 4 of F 1g through a ygroove 26 in the part Al'i and into the space formed at the right of the part 6 Where it Fllgure 5 1S a Sect-'lon on the hne 5 5 of Flg connects with a pitman, 21 attached to a crank u1`e 6 l h 6 f pin 28 on the gear I3. Thus as the gear I3 is 40 Fllgule s a Sectlon on t e Ime e 0 F 1g' rotated the saw carrier I9 is reciprocated as will 40 ure be seen.

In these drawings the numeral I indlcates a It Will also be seen that as the gear I3 is r0 tubular upright rising from a base 2 and the tated it win rotate the gear I2 whioh, in turn, numeral 3 mdlcates a Stationary Screw Shaft rotates the shaft llandsaid shaft passesinto having its lower end fastened in the Central a socket formed in the upper end of the screw 45 part 0f the base 2 and located in the Central pOrshaft s where the lower end of the shaft Il is tion of the tubular member I. The letter A indiformed with an enlargement 29 which is held in cates a frame which includes an elongated horithe Socket by Va nut 30 threaded in the top part of'L zontal part 6 and a tubular vertical part I eXtendthe socket. l

ing downwardly from one end of the part 6 and A plate 3| is supported in the upper portion of 50 this part 'l has a sliding iit in the tubular member the part I for limited vertical movement and is l. Adjacent'the lower end of the part I is a parheld against turning movement by the key means tition 8 which has a hole therein through which shown generally at 32 and the shaft II passes passes a tubular member 9 internally threaded to through a centrally arranged hole in the plate engage the threads of the member 3. An upper 3|. A pinion 33 is keyed to thev shaft II for slid- 55 ing but non-rotatable movement and said pinion meshes with a gear 34 on the upper end of a stub shaft journaled in the plate 3l and having a gear 36 on its lower end meshing with a gear 3l fastened to the upper end of the tubular shaft 9 so that turning movement of the shaft Il is communicated by said gearing to the tubular shaft l 9 and the rotary movement of this shaft 9 causes the same to move downwardly or upwardly on the stationary screw shaft 3 and as the parts associated with this shaft 9 are connected ywith the frame A said frame A is caused to movein a vertical plane with the shaft 9 and this movement of the frame A causes the blade 20 to move toward a piece to be sawed, placed under the saw orto be moved away from said piece.v

A spring Il@ surrounds the shaftl l andbears against the pinion-33 and the lowerface of the partition lil and a cam lll is formed on the bottom of the gear l2 and a cam groove 42 is formed in the upper face of the partition lll and extends over approximately half of said circular partition ill as shown in Figure 6, the groove having beveled lend walls 43 so .the cam il can move off the same as it leaves the groove or down a beveled end wall as yit enters the groove. This arrangement will cause the spring 49 Ybearing against thepartition I to raise the entire frame A when the cam vlll comes opposite the groove so that -the cam will enter the groove and this movement is sufficient to raise the blade 20 out of cutting position on the object being sawed and as thev groove 42 is of approximately half the circle formed by the member I9 the saw will make one stroke while in raised position and then just before it starts its next'stroke the cam'will ride lout the groove and thus the entire frame with the saw will be Apressed downwardly so that the teeth of the saw will engage the object and thus make a cut.

The major portion of the part '6 is of solid construction excepting the recess 24 and groove 2B and these parts are covered by va cover plate and at the free end of the part 6`is a handle grip member 4S.

A handle member is also attached to the tubular member lI but this handle member is not shown as it is located below the casing i5 in Figure 2. *This handle member enables the l parts to be manipulated'w'ithout touching the ymovablepart l. A box-like guiding lpart 48 is provided on the part 6 at the underside thereof for the front end of the saw frame, as shown in Figure land the cover plate 45 covers this guiding'portion and 'a small casing 49 extends from thepart 'l for enclosing the projecting part of the shank 2l of the saw.y

vThus it will be seen that the saw is, driven from the motor, though it can be driven by hand, and this motion is imparted to the saw ina reciprocatory motion and atthe same time the hollow vshaft 9` is rotated so .that it will move down on the stationary shaft 3, carrying the entire frame A with it so ,that lthe saw 4as it reciprocates and cuts through'an object is moved downwardly against the object. However, after Y each cutting stroke the cam 41, acts with the 'other parts to slightly raise the saw so that it that such changes fall within the scope of the appended claims.

Having described the invention, what is claimed as new is:

l. A hack saW comprising a base, a frame supported for vertical movement on the base and including a horizontalpart, a saw carrier supported for horizontal movement under the horizontal part, a blade carried by the carrier, means for reciprocating the carrier and at .the same time` moving. the Vframe downwardly to bring the blade against the piece to be out, and means for automatically raising the blade out of cutting position on one stroke of the carrier and. vvreturning it to 'cutting position for the next stroke, the latter means including a horizontal n part in the frame having a substantially semicircular groove therein, a rotary member forming part of the means for moving the frame downwardly and a cam on'saidrotary part for engaging the groove for `a partof the revolution o f the rotary member `and then engaging the horizontal member for the rest of the revolution" l and spring means for vmoving the horizontal part, and therefore the frame, upwardly, to cause the cam to engage the groove.v

2. A hack saw device of the class describedr` comprising a'tubular base, a vertically'arranged screw shaft supported against movement in the tubular base, a substantially L-shaped frame having a vertical part slidably fitting in the tubular base, a tubularv internally screw-threaded shaft carried by said vertical part and engaging the stationary screw shaft, ablade carrier supported ,for sliding movement in a horizontal plane on the other part of thegL-shaped frame, a motor, a gear rotated by the motor and located at the junction of the two Vparts of the L-shaped l frame, a pitman Yfor connecting the gear with the blade carrier and means connecting the-gear' with the tubular shaft for rotating the same.

l 3. A hack, saw device of the class described comprising Va tubular base, a'vertically arranged screw shaft supported against movement in the tubular base, asubstantially L-shaped frame having a vertical part slidably fitting in the tubular base, a tubular internally screw-threaded shaft carried by said vertical part and engaging the stationary screw shaft, a blade carrier supl ported for sliding movement in a horizontal plane on the 'other part of the` l shaped frame, a' motor, a gear rotatedby the motor and locatedl at the junction of the two parts of the L-shapedA ca V ing a tubular base, an L-shaped frame including. t

a horizontal part and a vertical part, the vertical part having sliding movement in the tubular base, a motor supported from the vI -shaped frame at the junction of the two parts thereof, the lvertical part and a portion of the horizontal part of the L- shaped frame being hollow, the

motor shaitfextendinginto the hollow part, a

gear connected with the inner. end of the motor shaft, a reciprocatory saw blade carrier-supported for sliding movement in a horizontal plane underthe horizontal part,l a pitman conn ected with the gear and with the carrier, a

stub shaft supported for rotary movement in the vertical part, a beveled gear at the upper end of said shaft meshing with the iirst mentioned gear, a stationary screw shaft in the tubular base, a tubular internally screw-threaded shaft in the vertical part fitting over the stationary shaft, gearing connecting the stub shaft with the tubular shaft for rotating the same and means for raising the frame slightly after the blade has made a cutting stroke and holding' the parts in raised position as the blade is taking its return stroke and then lowering the frame for enabling the blade to make a cutting stroke, such means including a cam on the second beveled gear and a semi-circular groove in a part of the vertical portion of the frame.

J OHN HENRY GU'ILTMAN. 

